The present invention relates to abrasive articles, more particularly to abrasive articles having an adhesive layer.
Many abrasive articles, for example, coated abrasive or nonwoven abrasive articles in the form of sheets or discs, are commonly mounted onto a support pad during use. Typically, the purpose of the support pad is to provide the abrasive article with the necessary foundation required for a particular abrading application. For example, if the abrasive article is to be employed at high pressure (e.g., for high stock removal applications), the support pad will typically be durable, heat resistant, and rigid. If the abrasive article is to be employed for finishing contoured surfaces, the support pad will typically be soft and conformable.
For abrasive articles having a backing, one option for mounting the abrasive article onto the support pad involves a pressure-sensitive adhesive (i.e., PSA). For this option, the surface of the backing opposite the abrasive layer typically bears a layer of PSA. The PSA layer typically has sufficient adhesion to hold the coated abrasive article on the support pad for the intended abrading application.
As supplied to the user, a liner is typically bonded to the PSA layer of the abrasive article. The liner serves, for example, to protect the adhesive layer from foreign matter that may otherwise adhere to the PSA layer resulting in a lessened tack of the adhesive layer. Conventional liners are typically made of paper or polymeric film, and generally have a coating of a low adhesion material. Typically, the low adhesion material is in direct contact with the PSA layer. Examples of such low adhesion materials include polyethylene, silicones, fluoropolymers, and high molecular weight waxy materials. Removal of the liner thereby exposing the PSA layer can be a tedious process, as it typically requires separating (e.g., using fingernails) the liner from the PSA layer.
To facilitate removal of the liner, some abrasive articles have a disposable tab. Such abrasive articles are commonly formed by cutting (e.g., by die cutting) the abrasive article, and its associated liner, into a shape corresponding generally to a preferred size and shape (e.g., a disk or rectangle), but including an additional area which forms the tab. A cut that is made through the abrasive layer, backing, PSA layer, and optional layer(s) of the abrasive article, but not penetrating the liner, severs that portion of the abrasive article on the tab from that portion having the preferred shape. The tab can be easily grasped and used to remove the liner from the PSA layer, resulting in an abrasive article having the preferred shape. In practice, it is difficult to accurately control the depth of the cut that separates the tab from the abrasive article, and problems with cutting into or through the liner are common. In such cases, the tab may not function properly.
In one aspect, the present invention provides a coated abrasive article comprising:
a backing having a first major surface and a second major surface opposite the first major surface;
an abrasive layer on at least a portion of the first major surface, wherein the abrasive layer comprises binder and abrasive particles;
an adhesive layer on at least a portion of the second major surface; and
a removable liner adhered to the adhesive layer, the liner comprising a base portion having protrusions extending therefrom, wherein at least some of the protrusions contact the adhesive layer.
In another aspect, the present invention provides a nonwoven abrasive article comprising:
a backing having a first major surface and a second major surface opposite the first major surface;
a nonwoven abrasive web on at least a portion of the first major surface, the nonwoven abrasive web comprising an open lofty fiber web, binder, and abrasive particles;
an adhesive layer on at least a portion of the second major surface; and
a removable liner adhered to the adhesive layer, the liner comprising a base portion having protrusions extending therefrom, wherein at least some of the protrusions contact the adhesive layer.
In another aspect, the present invention provides a method of making a coated abrasive article comprising:
providing a backing having a first major surface and a second major surface opposite the first major surface;
affixing an abrasive layer to at least a portion of the first major surface, the abrasive layer comprising a binder and abrasive particles;
affixing an adhesive layer to at least a portion of the second major surface; and
adhering a removable liner to the adhesive layer, the liner comprising a base portion and a plurality of protrusions extending from the base, by contacting the protrusions with the adhesive layer.
Typically, the abrasive layer is affixed to the first major surface prior to adhering the removable liner.
In another aspect, the present invention provides a method of making a nonwoven abrasive article comprising:
providing a backing having a first major surface and a second major surface opposite the first major surface;
affixing a nonwoven abrasive web to at least a portion of the first major surface, the nonwoven abrasive web comprising an open lofty fiber web, binder, and abrasive particles;
affixing an adhesive layer to at least a portion of the second major surface; and
adhering a removable liner to the adhesive layer, the liner comprising a first surface having a base portion and a plurality of protrusions, wherein the protrusions contact the adhesive layer.
Typically, the nonwoven abrasive web is affixed to the first major surface prior to adhering the removable liner.
In another aspect, the present invention provides a method of abrading a workpiece comprising:
providing a coated abrasive article comprising:
a backing having a first major surface and a second major surface opposite the first major surface;
an abrasive layer on at least a portion of the first major surface, the abrasive layer comprising a binder and abrasive particles;
an adhesive layer on at least a portion of the second major surface; and
a removable liner adhered to the adhesive layer, the liner comprising a base portion and a plurality of protrusions extending from the base, wherein the protrusions contact the adhesive layer;
removing the liner from the adhesive layer;
adhering the adhesive layer to a support pad;
frictionally contacting at least a portion of the abrasive layer with at least a portion of the surface of the workpiece; and
moving at least one of the abrasive article or the workpiece relative to the other to abrade at least a portion of the surface.
In another aspect, the present invention provides method of abrading a workpiece comprising:
providing a nonwoven abrasive article comprising:
a backing having a first major surface and a second major surface opposite the first major surface;
a nonwoven abrasive web on at least a portion of the first major surface, the nonwoven abrasive web comprising an open lofty fiber web, binder, and abrasive particles;
an adhesive layer on at least a portion of the second major surface; and
a removable liner adhered to the adhesive layer, the liner comprising a base portion and a plurality of protrusions extending from the base, wherein the protrusions contact the adhesive layer;
removing the liner from the adhesive layer;
adhering the adhesive layer to a support pad;
frictionally contacting at least a portion of the nonwoven abrasive web with at least a portion of the surface of the workpiece; and
moving at least one of the abrasive article or the workpiece relative to the other to abrade at least a portion of the surface.
Typically, liners of coated abrasive articles and nonwoven abrasive articles according to the present invention are easily removable and address the problem of inadvertent cutting of the liner during converting operations.